Tonight I voted to close my own question as a duplicate when I could have deleted both my zero voted question and self answer.
The reason I did this was because my question title: Why does `journalctl --list-boots` only show the current boot? was substantially different than the duplicate target: How to find previous boot log after Ubuntu 16.04 restarts?
Was it ok to vote to close my own question rather than deleting it?
I think I was using "signpost quantum theory of Zanna"--or something like that :)